NMR techniques have grown extensively over the past forty years, most notably in the medical instrumentation areas where in vivo examination of various parts of the human body may be seen and in clinical research laboratory uses. In addition there has been some application of these techniques to industrial instrumentation and control tasks, notably as described in the prior U.S. Pat. No. 5,015,954 of Dechene et al. issued on 14 May 1991 and U.S. Pat. No. 5,049,819 issued Sep. 17, 1991, of Dechene et al. both assigned to Auburn International Inc., Danvers Mass., the disclosures of which are incorporated herein by reference as though st out at length herein. The present invention enables the user to efficiently and effectively handle particulate solid samples of non-uniform composition (e.g. raisins, chocolate and nuts in cookies), texture and surface characteristics (e.g. "stickiness", and granularity).
Present techniques for handling non-uniform specimens (samples) call for separation of the various component parts e.g. raisons, nuts, crumbs, chocolate. Each component is placed in a test tube or other such holders with spatulas or whatever utensil seems to work. The analysis is performed on each component part, and the results are combined for reporting purposes. This separation leads to several sources of error including the following: (a) the relative proportions of the components parts are handled separately, (b) the analyses are performed at different times with different operators and instrument settings. To eliminate these errors, it is desirable to analyze the entire non-uniform sample at the same time. However this presents some problems.
For example there is a need to determine (using NMR techniques) the water content of a whole cookie, including the raisins, chocolate, sugar, nuts, crumbs, etc. The components are all different sizes and textures making it difficult to physically put them into the same test tube. Additionally some of the ingredients are sticky (sugar), some will crumble (nuts), some will not crumble (raisins), some will flow easily (crumbs), some will not flow (crushed raisins). Trying to get all the material into a test tube is not easily accomplished, and when the analysis is complete the material is not easily washed out of the test tube.
An object of the present invention is to provide an improved sample-chamber system, with load unload features, for handling particulate non-uniform solid samples for use in NMR instruments and the like.
It is another object of this invention to provide repetitive capture of a uniform, repeatable sample size which leads to accurate, fast determination of the types and quantity of the nuclear species of interest or like parameters.
A further object of this invention is to provide the ability to unload the sample and clean the chamber after analysis in a quick and easy manner.
Another object of this invention is to provide for fabrication of the holder from a material which is magnetically "invisible" (or otherwise invisible to other radiant energy fields that participate in the measuring) and non-active in the frequency and time domains, in relation to the sample, i.e. that will not interfere with the NMR analysis of the sample or modify the response of the sample itself.
Another object of this invention is to accommodate the variations of density, sample type and physical anomalies of diverse samples with an economical holder.